Deep Cycle Batteries – Off Grid Solar

Date: March 18, 2015

The decision between the type of deep-cycle battery for an Off Grid Solar system is often made financially. Typically because sealed deep-cycle batteries are more expensive than open-vented types. It is worth considering that just because one system may have a cheaper (smaller) battery bank, it will simply not last as long – meaning that you have to pay for another set – so it worth paying for it at the beginning…

Typically, deep cycle batteries for Off Grid Solar Systems have a life cycle depending on the frequency and depth of discharge. The more they are discharged, the less amount of times they can be charged and discharged – this is usually on a exponential curve. Meaning the less they are discharged the more amount of ‘cycles’ they can endure.

Some solar designers will compromise on the size of the battery bank, meaning that they will offer a large solar array compared to the battery bank – this can be misleading to consumers looking for an Off-Grid Solar System. It also makes comparing one system quote to another difficult.

As the battery bank is the heart of an Off Grid Solar System, it is pertinent to allow for sufficient deep cycle battery storage, for a few reasons; firstly, you want power at night when the sun has set – you want to the batteries to provide power to put the dishwasher on and to run entertainment equipment. Secondly, you want the batteries to deliver power when there are overcast days.

By compromising on the deep cycle battery component of an Off Grid Solar System, although it may be slightly less in comparison to other companies offers, the battery bank will certainly last less time i.e unto half the amount. Therefore, another investment in a set of deep-cycle batteries will put the cost up further than if the investment was made right in the first instance.

Another point to watch when researching deep cycle batteries is that many companies will state the amount of power available, typically in kW/hours or Amp-hours. They often state the amount of power available when the battery is completely ‘discharged’ – completely discharging at battery will severely affect its lie-cycle. An good example is how often a car battery will last after it has been discharged from leaving the car headlight on.

There are only a few batteries which can handle a complete discharge and they are often not found in Off Grid Solar systems as of yet – it may take a few more years to make these types commercially available. To continue reading more about deep cycle batteries for off grid power please click on the following link: